PORTLAND (AP) – Police were hunting for two brothers wanted as suspects in the fatal stabbing of a 16-year-old boy at his family’s Portland apartment.

Arrests warrants were issued for Brandon Mills, 20, who was charged with murder, and Antwane Mills, 18, charged with felony murder.

The victim, Jarmaine Ramirez, was stabbed Thursday afternoon when two men tried to push their way into the second-floor apartment on Congress Street where he lived with his mother and five siblings.

Police said Antwane Mills entered the building after being hit with liquid that youngsters were apparently throwing onto the street from a window in the apartment.

Mills left the area, only to return a short time later with his brother, police said. The pair, who don’t appear to have had any previous connection with Ramirez, went up the stairs and the fight followed.

Ramirez and his 22-year-old sister Isabel wrestled with the men until suddenly he shouted that he had been stabbed. He was taken to Maine Medical Center where he was pronounced dead a short time later.

Brandon and Antwane Mills are from the Dorchester section of Boston, but have lived in Maine for several months. The two previously were arrested on charges of disorderly conduct for allegedly fighting in Portland’s Old Port, police said.

Police have enlisted the help of Boston police and state police in Maine and Massachusetts in an effort to find the two suspects.

Ramirez was a sophomore at Portland High School who hoped to go on to college. Friends and family members described him as a quiet person who got along with everyone and helped his mother with the younger children.

“They took away the sweetest kid who never hurt anybody,” said Barbara Hollstrom, a cousin.